Senior Allison Glass had 19 digs, 18 kills and five aces in South Side's upset of three-time defending champion Wantagh in the Nassau Class A title match.

After pushing Wantagh to the limit in last year’s Nassau Class A girls’ volleyball final before falling in five sets, South Side defied tremendous odds to dethrone the three-time defending county champions in last Sunday’s title rematch at Adelphi University.

The second-seeded Lady Cyclones, who lost both regular-season meetings to the top-ranked Lady Warriors, overcame an eight-point deficit to win a pivotal third set on the way to a 17-25, 25-17, 25-22, 25-14 victory. Seniors Deanna Mostowfi (23), Allison Glass (19) and Allison Leonard (17), and sophomore Jackie Arcoleo (15) combined for 74 digs for South Side, which played stellar defense in capturing its first county crown since 2003.

“It’s the most amazing feeling,” said Glass, an All-State hitter who added 18 kills, including the championship-clinching point, and five aces. “We’ve never beaten Wantagh before, and that’s all I ever wanted to do.”

Lady Cyclones coach Cheryl Scalice started three sophomores — Arcoleo, Sydney Gabriel and Ashley DeTullio — and a fourth, Maya Shabbir, played an integral part in the second set, with five kills. All four underclassmen filled vital roles during the title run, Scalice said, after senior setter Emma Paris and junior hitter Kayla Principato suffered season-ending injuries in late September.

“It was a challenge,” Scalice said of replacing a pair of starters. “Our seniors did a great job helping the younger players develop. You never know how young players are going to react on a big stage, but they really stepped up. And we needed them.”

The Lady Warriors, who entered the finals having won 11 straight matches and who hadn’t dropped a set since Oct. 22, scored the opening five points and took the first set in convincing fashion behind the efforts of Carly Simeone and Anna Paulik. They also had an 11-8 lead in the second set, before Shabbir and senior Bridget Kiernan provided South Side with an offensive jolt that led the squad to take 17 of the next 23 points and even the match.